Harold H. Kung
Professor of Chemical and Biological Engineering
Education
Dorothy Ann and Clarence L. Ver Steeg Distinguished Research Fellow, Northwestern University, Evanston, IL
Post-doctoral Fellow, Northwestern University, Evanston, IL
Ph.D. Chemistry, Northwestern University, Evanston, IL
B.S. Chemical Engineering, University of Wisconsin, Madison, WI
Research Interests
Developing new materials and processes for a sustainable world is a challenging but rewarding goal. The current emphases of our research focus on novel catalytic materials reactions, which are integral parts of most environmentally friendly, energy- and material-efficient chemical processes, and on new materials for efficient energy storage, particularly electrical energy storage, that facilitates large-scale adaptation of renewable energy.
Highly efficient catalysts minimize energy consumption and environmental impact by reducing waste generation and material consumption and simplifying process complexity. The ability to design such catalysts relies on our level of understanding of catalytic reactions and the available synthetic tools. Our prospect to achieve this is greatly improved by the recent rapid advances in synthesis capabilities, consequence of developments in nanotechnology, and in atomistic characterization of catalytic systems. They enable design and synthesis of catalytic materials that model after natural enzymes, which are among the most active and selective known catalysts.
Our group has been acquiring the skill set needed to introduce enzyme-like functionalities into nonbiological materials so as to capture the reactivity and reaction specificity of the enzymes without the constraint of sensitivity to processing conditions that they exhibit. Currently, we focus on the design and synthesis of catalytic materials that exhibit two unique properties of enzymes: cooperative effect in which two or more functional groups interact cooperatively to enhance the catalytic activity and specificity, and confinement effect which manifests the influence on the immediately surroundings on the properties of the active center. We have successfully completed the first synthesis of an asymmetric bicyclic siloxane, as well as spherical nanocages of siloxane and carbosilanes with interior functional groups and molecular size-selectivity for access to the cage interior. Our current activity includes designing structures that anchor multiple functional groups to understand the conditions for cooperativity, and apply these structures to reactions normally catalyzed by enzymes, including hydrolysis of cellulose. We are also extending the concept to reactions that are not commonly found in nature but industrially important.
Rechargeable Li ion batteries are the most promising, high capacity electrical energy storage device available. However, there is a huge potential to improve their capacities significantly with new electrode materials, both at the anode and the cathode. Some of the known high capacity materials, however, suffer from rapid degradation. We are applying our synthetic background acquired in our study of catalytic materials to construct new forms of electrodes that could stabilize the storage components. For example, we have greatly reduced the rapid agglomeration of silicon nanoparticles by encapsulation in an organic polymer, such that the high Li storage capacity of Si can be realized for a much extended period. We are currently examining other stabilization techniques, as well as explore new materials as cathodic storage components.
Selected Publications
- C. M. Hayner, X. Zhao and H. H. Kung, “Materials for rechargeable lithium-ion batteries”, Annual review of chemical and biomolecular engineering, (2012)
- J. Lu, B. Fu, M. C. Kung, G. Xiao, J. W. Elam, H. H. Kung and P. C. Stair, “Coking- and Sintering-Resistant Palladium Catalysts Achieved Through Atomic Layer Deposition”, Science, (2012)
- M. C. Kung, S. S.-Y. Lin and H. H. Kung, “In situ Infrared Spectroscopic Study of CH4 Oxidation Over Co-ZSM-5”, Topics in Catalysis, (2012)
- M. N. Missaghi, M. C. Kung and H. H. Kung, “Polysiloxanes in Catalysis and Catalyst Preparation: Opportunities for Control of Catalytic Processes”, Topics in Catalysis, (2012)
- X. Zhao, C. M. Hayner, M. C. Kung and H. H. Kung, “Flexible Holey Graphene Paper Electrodes with Enhanced Rate Capability for Energy Storage Applications”, Acs Nano, (2011)
- X. Zhao, C. M. Hayner, M. C. Kung and H. H. Kung, “In-Plane Vacancy-Enabled High-Power Si-Graphene Composite Electrode for Lithium-Ion Batteries”, Advanced Energy Materials, (2011)
- T. Yoon, C. Chae, Y.-K. Sun, X. Zhao, H. H. Kung and J. K. Lee, “Bottom-up in situ formation of Fe3O4 nanocrystals in a porous carbon foam for lithium-ion battery anodes”, Journal of Materials Chemistry, (2011)
- X. Zhao, C. M. Hayner and H. H. Kung, “Self-assembled lithium manganese oxide nanoparticles on carbon nanotube or graphene as high-performance cathode material for lithium-ion batteries”, Journal of Materials Chemistry, (2011)
